package com.xyz.jucTest;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class ShareResource{
    /**
     * 1:A  2:B  3:C
     */
    private int number =1;
    private Lock lock=new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();

    public void print5(){
        lock.lock();
        try {
            //判断
            while (number!=1){
                condition1.await();
            }
            //干活
            for (int i=1;i <= 5;i++){
             System.out.println(Thread.currentThread().getName()+i);
            }
            number = 2;
            //只通知 condition2 里的线程干活
            condition2.signalAll();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
    public void print10(){
        lock.lock();
        try {
            //判断
            while (number!= 2){
                condition2.await();
            }
            //干活
            for (int i=1;i <= 10;i++){
                System.out.println(Thread.currentThread().getName()+i);
            }
            number = 3;
            //只通知 condition2 里的线程干活
            condition3.signalAll();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
    public void print15(){
        lock.lock();
        try {
            //判断
            while (number!=3){
                condition3.await();
            }
            //干活
            for (int i=1;i <= 15;i++){
                System.out.println(Thread.currentThread().getName()+i);
            }
            number = 1;
            //只通知 condition2 里的线程干活
            condition1.signalAll();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

}

/**
 * @author 肖咉卓
 *
 * 精准控制
 *
 * 多线程之间按顺序调用，实现A->b->c
 * 三个线程启动，要求如下：
 * A答应5次，B打印10次，C打印15次。来10轮
 *
 * 1   高聚低合前提下，线程操作资源类
 * 2   判断/干活/通知
 * 3   多线程交互中，必须要防止多线程的虚假唤醒,也即（必须要要用 while 来判断，不能用if）
 * 4   注意标志位
 */
public class ThreadOrderAccess {
    public static void main(String[] args) {
        ShareResource shareResource=new ShareResource();

        new Thread(() ->{for (int i=0;i<10;i++){shareResource.print5();}},"A").start();
        new Thread(() ->{for (int i=0;i<10;i++){shareResource.print10();}},"B").start();
        new Thread(() ->{for (int i=0;i<10;i++){shareResource.print15();}},"C").start();
    }
}
